DOI: 10.5152/EurJTher.2017.163 European Journal of Therapeutics Use of botulinum toxin in urology: a literature review Ömer Bayrak 1 , İlker Seçkiner 1 , Rahmi Onur 2 , Roger Roman Dmochowski 3 1 Department of Urology, Gaziantep University School of Medicine, Gaziantep, Turkey 2 Department of Urology, Marmara University School of Medicine, İstanbul, Turkey 3 Department of Urology, Vanderbilt University Medical Center, Nashville, USA ABSTRACT Botulinum neurotoxin (BoNT) is currently preferred as a minimally invasive treatment for lower urinary tract pathologies. Although BoNT injections have become widespread globally for the past 5 years, today, the urological use of BoNT Type A (BoNT-A) is only licensed for the treatment of neurogenic detrusor overactivity and overactive bladder. Despite the relative evidence for the use of BoNT-A in benign prostatic enlargement, there is no high-level evidence data for the use in detrusor sphincter dyssynergia, inter- stitial cystitis/bladder pain syndrome, and chronic pelvic pain. In this comprehensive review, we mention the mechanism of action and efficacy of BoNT in various urological disorders, present the reliability, and evaluate the literature data supporting its use. Keywords: Botulinum toxin, neurogenic detrusor overactivity, overactive bladder, detrusor sphincter dyssynergia, benign prostat- ic enlargement, interstitial cystitis Corresponding Author: Ömer Bayrak E-mail: dromerbayrak@yahoo.com Received: 21.07.2017 • Accepted: 20.09.2017 INTRODUCTION Botulinum neurotoxin (BoNT), a protein produced by Clostridium botulinum, an anaerobic gram-positive bacterium, is a potent neu- rotoxin. Clinical manifestations are caused by infection through contaminants (particularly canned food prepared at home), meat, sausage, and gastrointestinal tract infection or gastrointestinal colonization in infants with open bruises (1). After discovering that food poisoning in the nineteenth century was usually caused by homemade sausages, this toxin was named as “Botulinum toxin” after the Latin term “Botulus” meaning sausage (2). Toward the mid-1900s, BoNT Type A (BoNT-A) was injected in a hyperactive muscle, and it blocked the motor nerve stimulation by inhibiting acetylcholine release from the presynaptic end thus causing paralysis (3, 4). These developments inspired the use of BoNT in the treatment of various other diseases resulting in an increasing number of studies exploring the efectiveness of this treatment method. In 1973, Scott (5, 6) published a study of the efects of BoNT on rectus lateralis in monkeys, and in 1981, he reported the frst administration of the toxin on human sub- jects by treating patients with strabismus. Following the Food and Drug Administration (FDA) approval of the use of BoNT-A in the treatment of eye disorders in 1989, the use of BoNT for initial treatment was successfully implemented for strabismus, benign essential blepharospasm, and hemifacial spasm (7). Botulinum neurotoxin was subsequently used in a wide range of indications, including urological pathologies. The use of BoNT in- jections on the external urinary sphincter in patients with detru- sor sphincter dyssynergia (DSD) who had spinal cord injury (SCI) was frst diagnosed by Dykstra (8) in 1988. The use of BoNT-A by Schurch et al. (9) in the same group of patients accelerated the work in this area and opened the way for further developments. Currently, BoNT can be used in urological pathologies, such as overactive bladder (OAB), neurogenic detrusor overactivity (NDO), interstitial cystitis (IC)/bladder pain syndrome (BPS), DSD, benign prostatic hyperplasia (BPH), and chronic pelvic pain (CPP; Table 1). However, the FDA approval of BoNT treatment for only OAB and NDO has been obtained from these pathologies (10-12). In this comprehensive review, we mention the mechanism of action and efcacy of BoNT in various urological disorders, present its reliabil- ity, and evaluate the literature data supporting its use. CLINICAL AND RESEARCH CONSEQUENCES Types of Botulinum Toxin Botulinum neurotoxin is a neurotoxin secreted by Clostridium botulinum, which is a gram-positive, anaerobic, spore-forming, rod-shaped bacterium. Immunologically, 7 active subtypes of A, B, C, D, E, F, and G have been identifed. Today, the most com- monly used subtypes are BoNT-A and Type B. Numerous compar- ative studies have demonstrated that Type A is more potent and long-acting than Type B (10-14). The commercial forms containing BoNT-A used in clinical practice are onabotulinumtoxin A (Botox®; Allergan, Dublin, Ireland), abobotulinumtoxin A (Dysport®; Ipsen-Biotech, Paris, France), incobotulinum toxin A (Xeomin®; Merz Pharmaceuti- cals, Frankfurt, Germany). The dose equivalency of Botox® and Dysport®, the 2 preparations used in our country, is approxi- mately 1 to 3-5 (15, 16). 131 Review